WAUKESHA, Wis. — The city of Waukesha has submitted an updated application to Wisconsin’s Department of Natural Resources for permission to use Lake Michigan for its drinking water.

The Milwaukee-area community is under a federal order to find a new source because the underground aquifer it uses is tainted with radon.

The city is only 15 miles from Lake Michigan but outside its watershed, although it’s in a county that straddles the line. A regional compact requires that such outliers get permission from all eight states that drain into the Great Lakes before withdrawing their water.

Dan Duchniak of the Waukesha Water Utility said Monday that the revised application updates the city’s conservation plan. He said Waukesha would return as much treated water to the lake as it removes.